Varying concentrations of antibiotic and cosubstrates in influent were conducted to test the antibiotic removal efficiency and the microbial fuel cell(MFC)performance. The results show that the mechanisms of microbial fuel cellconstructed wetland(MFC-CW)to remove sulfamethoxazole(SMX)and tetracycline(TC)are mainly adsorption and microbial degradation, respectively. The tetracycline has a strong polarity, thus it can be absorbed immediately and stably after entering the system. Sulfamethoxazole is easier to flow with water and can easily microbial degradation. The higher concentration of antibiotic in influent is observed and detected in the effluent corresponding to the decrease of the system open circuit voltage. Meanwhile, the ability of the system on removing antibiotics is depending on the co-substrate concentration for altering performance of the system. With the increase of the co-substrate concentration, the open circuit voltage and internal resistance increase, while the coulombic efficiency of system gradually declines. Further analysis shows that when concentrations of antibiotic and cosubstrates are controlled within a certain range, the system can achieve the optimum balance in the electricity generation and the degradation of antibiotics.